Another 5.3 with AFM bites the dust ~ Chevrolet Active Fuel Management Problems

Discussion in 'GM Powertrain' started by hblock72, Jan 19, 2013.

  1. hblock72

    hblock72 New Member

    Bought truck new- 2007 Silverado Crew Cab LTZ Z71 4x4 with 5.3 and active fuel management.

    All was great for a while, first new vehicle I'd ever owned.

    At 54,500 miles check engine light comes on and has misfire-dealer diagnosed as no compression on cylinder7, Replaced collapsed lifter.

    At 80,300 miles check engine light comes on and engine develops loud knocking-dealer diagnosed agressive lifters/lifter oil filter dirty/P0521 oil pressure sender fluctuation, they replaced all left side lifters.

    At 90,800 miles check engine light comes on yet again-dealer diagnosed as another P0521 code and replaces sending unit. Although this time I have to pay for it as it's considered an electrical component and not covered under the 100,000 mile powertrain waranty.

    At around 100,000 miles oil consumption starts getting bad. Close to a quart every 1000 miles. Looking back and after reading up on this topic, I figure this started much earlier, I just didn't think much of it at the time.

    Now at 116,500 miles check enigne light comes on with misfire-dealer diagnosed as needing tune up (spark plugs, wires, and intake manifold cleaning) and quote me $720.00. This didn't seem right to me, but I told them to go ahead if that would fix it. Then get a call the following day that two cylinders have no compression and they are recommending an engine replacement to the tune of $7200.00.

    I had hoped to just get the thing fixed enough to get rid of the check engine light so it would pass the state inspection then trade it off in the next few months. Now here I sit with a nice $40k truck that is otherwise in great shape and I've been happy with except for the engine which appears to be a complete lemon.

    Looking for some opinions here. Obviously i'm not crazy about having to spend $7200. Although I'm supposed to get a call from the service manager on monday to see if he can do anything. Service writer couldn't do much. I'm hoping the dealer can work with GM and they'd be willing to at least reduce the price some, but won't be holding my breath. Seems like I don't have much choice other than to replace the enigne since it's only worth it's weight in scrap metal as it sits. Maybe with a new engine I could go another 3-4 years before getting another vehicle. I'd pretty much have to after sinking that much money into it. Could consider a junk yard engine and a shade tree mechanic, but that seems kinda iffy to me as well. Thoughts???
    Last edited by a moderator: Jan 24, 2013
  2. Enkeiavalanche

    Enkeiavalanche Loving the Outdoors Staff Member 5+ Years ROTM Winner 5000 Posts

    First off Welcome....

    Alot of us have been getting problems with our 5.3 motors and the Great GM CRAP computer controlled AFM. I'm getting my motor rebuilt in the next few weeks and now (I think) because of a Heavy Blue smoke one of my 02 Sensors are bad but they tell me they will not cover it.. The service writer I have known for over 20 years and he knows ALL of my past GM trucks have gone over 100K with NO motor problems...:grrrrrr: I told him right out Fix it or the truck goes THROUGH the new Windows they are putting in now at the dealership!!!I've got 90K on it and I will not stand for this CRAP!!!

    I am taking this as High in GM as I can.. As a member of SEMA I know some higher people at GM and will be sending them all Letters...

    You know the saying.. Something good happens you tell 2-5 people, Something bad you tell 8-10 people...

    ME!!! :grrrrrr: Something like this!!! I tell the WORLD!!!!!!:gasp:

    I also just replaced my Evap that we are all having problems with... My dealer said they are doing a few a week.. WE should NOT have to pay for this.... GM knows of the problem...
  3. Sierraowner5.3

    Sierraowner5.3 Epic Member 5+ Years 1000 Posts

    makes me want to go into the tuner and turn the AFM off. this is scaring me alot. i dont have the mileage you guys do, so it shouldnt be an issue for a while regardless, but its still not good. this makes me wonder if the 6.2s in the vortec maxs are having these same issues as well, i would guess not since they are not AFM engines.

    @hblock72 - sorry to hear of your troubles. seems like GM owes ya something. you might try a salvage yard and see if you can find a lower mileage 5.3 donor engine.

  4. GM Customer Service

    GM Customer Service Epic Member 5+ Years 500 Posts


    Could you DM me your information (full name, number, address, VIN, current mileage, and involved dealer) along with any other additional information on your issue so I can look into your situation?

    Evan, GM Customer Service

    - - - Updated - - -


    I'm sorry to hear about your issues. If you would like to send me your information, I could check in with your dealership?

    Evan, GM Customer Service
  5. TRPLXL2

    TRPLXL2 Epic Member 5+ Years 1000 Posts

    What state do you live in?? I live in Ohio, and I have bought multiple engine from cleveland pick a part. They are a salvage yard that specializes in LS engines. I have bought 3 from them, and they have all been like brand new no problems. They have a Trailblazer SS 6.0 liter 4l80e dropout with 38,000 miles on it right now for $4,000 COMPLETE pedals, ecm, harness and all. That engine is 400 hp, and was more fun to drive than your 5.3 AND no more VVT crap!!!

    Just a thought, no way I would spend $7,200 for a 5.3 when there are a ton of options out there.
  6. stchman

    stchman Active Member 2 Years 1000 Posts

    The 6.2L on the Silverados and Sierras(non-Denali) do not have AFM. The Denali and Escalade with the 6.2L have AFM.
  7. Sierraowner5.3

    Sierraowner5.3 Epic Member 5+ Years 1000 Posts

    yep, knew that, thanks tho!

  8. stchman

    stchman Active Member 2 Years 1000 Posts

    Am I lucky? My 2008 Silverado with the 5.3L engine was trouble free when I traded it in with 73K miles. The only thing my 08 did was use ~1qt of oil every 5-6K miles. My 2013 with 3500 miles (changed oil at 1K) is still on the full mark.
  9. jake's silverado

    jake's silverado Epic Member 5+ Years 500 Posts

    Well you do still have a 5.3 right? I'm more lucky I think, now having a 6.2 2500 HD. :lol:

    Now how many have toasted themselves?
  10. Enkeiavalanche

    Enkeiavalanche Loving the Outdoors Staff Member 5+ Years ROTM Winner 5000 Posts

    I will PM you all the info.. Hope you can help with this motor/AFM thing and now the 02 Sensor that I think went bad because of the Blue/Oil smoke from the first problem...

    Thanks Glenn

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